928 HP on the chasis dyno today - Thanks Otto

[WIKEDV6]

Congrats Allan, it's freaking awesome. Many of us could only dream of making that kind of power and knowing that there is more power to be had is even more scary!

Prasad

 

[Blazer406]

It just tweeks me when people say that it's impossible to use a relatively high duration, high overlap camshaft in a turbo application. That's completely false. It's more involved to be successful doing it, but it's not 'impossible'.

My original comment was a question about if the older high overlap big (probably too big in many cases) cams bled off too much cylinder pressure at the low RPM's thereby hurting spoolup. I would think dynamic compression ratio would play a significant role in "spoolability" of a particular combo...... to a similar extent as huge port heads vs. small port heads.

 

[turbobitt]

Congrats Allan, it's freaking awesome. Many of us could only dream of making that kind of power and knowing that there is more power to be had is even more scary!

Prasad

Thanks for your complements. Based on my calculation, I will run into injector limitations at 1150 RWHP. That would be 90% duty cycle with 160#/hr. I think this will be my cut-off point.

Allan G.

 

[Alky V6]

Don. What Allan is trying to do is impossible when your not relying on a 300 shot of nitrous to spool.

I'm just trying to get the point across that if the proper combination is well thought out, overlap can be effective with a turbocharged engine. Will it work with any of the mass produced exhaust headers out there in the market? Absolutely not. I don't care what intake volumes you use, if you're not willing to take the whole engine package into consideration when attempting pulse tuning, then don't waste your time and stick to the simple cam grinds. And, don't try to tell me it's impossible. Anyone is welcome to visit my shop and inspect the proof I have sitting on the rack.
BTW, Dusty, that's a 400 shot.

My original comment was a question about if the older high overlap big (probably too big in many cases) cams bled off too much cylinder pressure at the low RPM's thereby hurting spoolup. I would think dynamic compression ratio would play a significant role in "spoolability" of a particular combo...... to a similar extent as huge port heads vs. small port heads.

High overlap and duration will make spooling more difficult, even if the compression ratio is raised to compensate. You're right about cylinder pressures being cut drastically. The higher CR will help, but it still won't help enough and the higher CR will just limit your max boost level for the engine. Everything is a compromise with a turbo engine. I chose to make my engine as efficient on the top end as possible with the heads I chose to use for the project. Nitrous was always part of the planned combination from the start. It is very effective for making up for the shortcomings of the combination on the low end. The best of both worlds. Efficiency on the top end without limits, and the ability of a 224 cid V6 to spool a T6 91mm turbo that would make any person jealous, regardless of what cam they were using. All it takes me is a 1.32 sec shot of nitrous and she's ready to fly.
I read long ago that nitrous and turbocharging were the perfect marriage. I intended to find that out for myself. Folks,... they were right.

One other nice thing about big cams. They help keep you out of trouble with a combination that would tend to create too much cylinder pressure through the spooling up period. Having the boost ramp up too quickly in relation to engine rpm. I hate replacing head gaskets and I wanted to steer clear of that possibility. That would tend to really be a problem if a person was playing around with large shots of nitrous with a small cam trying to get the turbo to spool too quickly in relation to engine rpm.

 

[turbobitt]

Ok, would like to keep this back on topic.

First, I would like to plug Jack Cotton for the help he has given me. He has always supported my build and been my primary source for stuff when I needed it. Most recently had my Aeromotive pump rebuilt and sent back at a reasonable cost.

Now it looks like upgrading to the Billet 91mm wheel is going to be a reality. I been working through Jack with Turbonetics to find the best solution to the airflow demands that I require. The billet 88mm wheel they currently offer should get me there but it also may be borderline. Based on my discussions with them, I don't think it will be a noticable hit on spool-up. I have some good baseline data to compare so we will see.

Allan G.

 

[GetOwnedVette]

I seem to see alot of threads make mention of A1000 pump rebuilds....They are kinda getting a reputation for failing. What is exactly going bad on them?

Ok, would like to keep this back on topic.

First, I would like to plug Jack Cotton for the help he has given me. He has always supported my build and been my primary source for stuff when I needed it. Most recently had my Aeromotive pump rebuilt and sent back at a reasonable cost.

Now it looks like upgrading to the Billet 91mm wheel is going to be a reality. I been working through Jack with Turbonetics to find the best solution to the airflow demands that I require. The billet 88mm wheel they currently offer should get me there but it also may be borderline. Based on my discussions with them, I don't think it will be a noticable hit on spool-up. I have some good baseline data to compare so we will see.

Allan G.

 

[Alky V6]

Ok, would like to keep this back on topic.

First, I would like to plug Jack Cotton for the help he has given me. He has always supported my build and been my primary source for stuff when I needed it. Most recently had my Aeromotive pump rebuilt and sent back at a reasonable cost.

Now it looks like upgrading to the Billet 91mm wheel is going to be a reality. I been working through Jack with Turbonetics to find the best solution to the airflow demands that I require. The billet 88mm wheel they currently offer should get me there but it also may be borderline. Based on my discussions with them, I don't think it will be a noticable hit on spool-up. I have some good baseline data to compare so we will see.

Allan G.

I agree. The 88 would be borderline, but sufficient for your target hp level.

 

[turbobitt]

I seem to see alot of threads make mention of A1000 pump rebuilds....They are kinda getting a reputation for failing. What is exactly going bad on them?

Pump did not fail. I don't think it was the A1000 but the pro series. My pump was 11+ years old and had a serial number 0025 or something like that. It was able to support 838 HP but was turning very slow under the high pressure demand.

Allan G.

 

[marleyskater420]

Pump did not fail. I don't think it was the A1000 but the pro series. My pump was 11+ years old and had a serial number 0025 or something like that. It was able to support 838 HP but was turning very slow under the high pressure demand.

Allan G.

Was the pump reaching its limits of flow capacity? Just curious.

 

[turbobitt]

Was the pump reaching its limits of flow capacity? Just curious.

The pump was old and worn out, so in that respect it reached its flow capacity. I replaced it with the same pump only new and continued the dyno pulls a few weeks after.

From what I understand, the pump had some internal design changes that increased the flow capacity.

Allan G.

 

[bison]

Was the pump reaching its limits of flow capacity? Just curious.

It was done at 838whp before the rebuild. Without raising the baseline fp he still has room to go. It's not a good thing to use a dyno to analyze a pumps capacity. There is no g force acting against a rear mounted pump for one and there is no knowing of the initial load on the pavement. First couple passes will be 60'. Then a couple 330', 660, and so on. Checking plugs and watching the logs. It's not likely that his un-rebuilt pump would support over 800whp on the pavement.

 

[turbobitt]

Another interesting find on my logs is that the PTC converter had less than %4 slip at the 800HP level near peak power. We didn't log DS RPM on the second day of pulls so I have no slip numbers at 900HP+. I'm sure this is no surprise to Dusty !!!

Allan G.

 

[marleyskater420]

It was done at 838whp before the rebuild. Without raising the baseline fp he still has room to go. It's not a good thing to use a dyno to analyze a pumps capacity. There is no g force acting against a rear mounted pump for one and there is no knowing of the initial load on the pavement. First couple passes will be 60'. Then a couple 330', 660, and so on. Checking plugs and watching the logs. It's not likely that his un-rebuilt pump would support over 800whp on the pavement.

That makes a lot of sense. Thanks for explaining that.

 

[baadgn]

Allan,

That number will go up once you get on God's dyno, but im sure it will still fall in the 6-7% range under full power at the traps. Cant wait to see that beast at the track

 

[turbobitt]

Allan,

That number will go up once you get on God's dyno, but im sure it will still fall in the 6-7% range under full power at the traps. Cant wait to see that beast at the track

Thanks Tony,

Been a long time since I been to the track. Hope it can actually make it down the track.

BTW, I been hearing a lot of good things about your car. Can't wait to see it in person.

Allan G.

 

[turbobitt]

Thought I would resurrect this thread. I spec’d a new cam and was going to shelve it for the next convenient time to install it. It appears that Bison is twisting my arm to install it now and ready the cam for another dyno session. You suck Bison !!!
So, now I am thinking of my next limitations on power. It looks like the single Aeromotive pump will be the next hurdle. I have another if I wanted to feed both sides of the rail. I could raise the base fuel pressure to get some more flow from the injectors.
Ultimately want to make 1150 at the tire. Should be able to accomplish this with one pump and keeping the base fuel pressure setting where it is. I also think that with the new compressor change, along with the new cam, that I should be able to get there at or before 35# boost.
I will try and update on the progress. If we go back to the dyno, it won't be until spring. Car is scheduled to go back to the paint booth before x-mass.

Allan G.

 

[turbobitt]

Changed out the cam today with Bison. Bison found something very interesting while I was buisy with mounting the degree wheel. I know he took some pictures and hope he posts it.

Allan G.

 

[turbobitt]

Changed out the cam today with Bison. Bison found something very interesting while I was buisy with mounting the degree wheel. I know he took some pictures and hope he posts it.

Allan G.

Bison just sent me the picture. Found a broken valve spring on #4 intake. Now we are questioning when it broke ??

Note: The top of the spring is not touching the retainer !!!! Didn't appear to do any damage to anything. Pistons look clean and so do the pushrods and rocker adjusters.

Allan G.

 

[norbs]

Wow, this could be the reason your down on power a bit at the higher boost levels?

 

[turbobitt]

Wow, this could be the reason your down on power a bit at the higher boost levels?

Ya, would sure love to know when it broke. We took another look at the data logs and cylinder temps and couldn't find anything conclusive. Will have to make some calls with Isky about the springs. These were supposed to be there "SP" or special process springs for endurance applications. Does not give me much confidence on the other springs.....

My Palm-O-Meter tells me it has about 90 lbs or less at the seat.

Allan G.